The present invention relates in general to on-chip magnetic devices, and more specifically, to on-chip magnetic structures, e.g., a laminated magnetic inductor stack, including magnetic materials having multiple permeabilities.
Inductors, resistors, and capacitors are the main passive elements constituting an electronic circuit. Inductors are used in circuits for a variety of purposes, such as in noise reduction, inductor-capacitor (LC) resonance calculators, and power supply circuitry. On-chip magnetic inductors are important passive elements in applications such as on-chip power converters and radio frequency (RF) integrated circuits. Inductors having magnetic core materials with thicknesses ranging several 100 nm to a few microns can be implemented to achieve a high energy density. For example, to achieve the high energy storage required for power management, on-chip inductors can require relatively thick magnetic stacks or yokes (e.g., several microns or more).